Improved bridge



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Letters Patent No. 94,322, dated August 31,1869.

IMPROVED BRIDGE.

The Schedule referred to in these Letters Patent and making part of the m- To all whom it 4may concern.:

Be it known that we, JOHN LAIRD and G. F. LAIRD, of Canton, in the county ot' Stark, and in the State of Ollio, have invented certain new and` useful Improvements `in Vrought-Iron Bridges; and do hereby declare that the following is a full, clear, and exa-ct description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

The nature of our invention consists in the construction and general arrangement of a wrought-iron bridge; and in order to enable others skilled in the ait to which our invention appertains to make and use the same, we will now proceed to describe how it isor may be constructed, referring to theannexed drawings, which form a part of this speciiication, and in which- Figure 1 is a side view, and

Figure 2 a. plan View of the bridge.

Figure 3 is a cross-section of the arch, and

Figure 4 is an end View of the inside-supporting block.

VA A represent the piers or abutnients, supporting the arches of the bridge.

On these piers, the shoes B B are tirinly secured.

C represents the span, which consists of two bars of iron, placed side by side a suitable distance apart, and connected at the ends by means of bolts. Between the. ends ot' said bars is inserted a T-shaped bar, a, or a straight bar, witha block on each side of its-outer end, forming the arms of the T.

The ends oi' the span G, thus formed, are let into correspondiugly-cnt slots in the lshoes B B, thus effect uallypreventing any separation ot the piers or abutments A A.

The arch oi' the bridge is constructed of ehannelled side-beams b b, placed a suitable dista-nce apart, and covered ou the upper side with plate-iron, d. The beams b b are channelled on the outside, and fastened together Vby bolts e e, which pass through the saule,

and through supporting-blocks c c, placed in the channei, on the outer side of each beam. Between the beams is placed an inside-supporting block, f, through which the bolts e e pass, and against which the beams bear. when fastened by said bolts.

IVe fasten the beams b b together at intervals or regular distances, throughout their entire length, with such inside and outside-supporting blocks and bolts.

The plate-iron d is secured to the channelled beams b b, by rivets through said plate-iron and the upper flanges of the beams.

The ends of the arches, thus constructed, are placed on the inner sides of the shoes B B, said shoes being bevelled and notched, as shown in tig. 1, to admit the channelled beams b 'b.

A suitable system or series of braces connects the arches with the span,l strengthening the bridge.

I'n addition to these, we use braces or rods m m, extending froni about the centre of the spans C C, and braces or rods n 11,'extending inward from the inner corners of the shoes B B.

Two of the braces, mm, and the braces n n, at each end of the bridge, pass through a ring, p, inside of which nuts are placed on the ends of said braces or rods, by means of which the whole structure is materially strengthened.

Having thus fully described our invention,

Nhat we elaiin as new, and desire to secure by Letters Patent, is-

1. The combination of the channelled beams b b, plate-iron d, outside-supporting blocks c c, inside-supporting blocks f f, and bolts e e, all constructed and arranged substantially as shown and described.

2. The arrangement of the beams b I1, iron d', blocks c c and j' f, shoes B B, spans C G, and bars a a, all as herein shown and described. l

1n testimony that we claim the foregoing, we have hereunto set cui` hands, this 9th day of February, 1869.

JOHN LAIRD. G. F. LAIRD.

Witnesses:

` GEO. W. RAFF,

W. A. KNAPP. 

